Risk Assessment of Allergic Diseases Among Preschool Children in Guangzhou, China: A Cross-Sectional Study.

Nearly half of the children in the region suffer from allergic diseases. Sex, birth order and full-term delivery all contributed to early childhood allergy. Family history of allergy, especially maternal, was the most important risk factor, and the number of family members with allergy was significantly associated with the allergy in children. Maternal effects are also reflected in prenatal conditions such as unplanned pregnancy, smoke exposure, pregnancy complications, and prenatal stress.